Exogenous Putrescine-Mediated Modulation of Drought Stress Tolerance in Sugar Beet: Possible Mechanisms

Abstract

Drought management is a major challenge under changing climate conditions, and improvement in drought tolerance is the ultimate goal for scientists working in varietal development. Drought stress has a severe effect on the growth and development of sugar beet seedlings, leading to an enormous reduction in total biomass accumulation. Polyamines (PAs) are low-molecular weight positively charged aliphatic polycations, and putrescine (Put) is the central product in PA biosynthesis pathway and also acts as a precursor of Spd and Spm, which are widely used for stress management in various crop. Due to their chemical structure, PAs are polycationic in nature, which modulate the ion balance in cells and bind with polyanionic molecules like DNA, RNA, proteins, or membrane, thus preventing macromolecule and cell degradation membranes under adverse conditions. The binding properties exhibit the ROS scavenging capacity of PAs, which confers the antioxidative role that can prevent the cell from being damaged by lipid peroxidation and ROS generation. Therefore, the application of Put on sugar beet may be a helpful tool for stress mitigation that increases the yield and quality without any harmful effect on plants and the environment.